Shah Rukh Khan and Katrina Kaif's 'Ishq Shava' is the second track to release from Jab Tak Hai Jaan.

A number of Bollywood playback singers including Udit Narayan, KK and Anushka Manchanda have contributed vocals to the upbeat, fusion song.

"'Ishq Shava' is one of the highlights of the soundtrack," a source told Digital Spy. "Udit Narayan is of course a fan favourite - and for many his voice is the perfect match for Shah Rukh Khan. There's also a melodious Spanish guitar.

"The video is very edgy, with SRK and Kat performing with freestyle dancers in an underground club and on board a boat on the River Thames. The lyrics to the chorus are picturised on Khan and the dancers. 'Ishq Shava/ Ishq Shava/ Ishq Shava/ Hey.'"

Khan's look in the video has been created by designer Shiraz Siddiqui and Kaif's by Manish Malhotra.

"SRK has been given a hip, street style in a checked shirt, and jeans tucked into boots," added the source.

"Manish has ramped up the glam for Katrina with a Comme De Garcon red leather bolero jacket, but has teamed this with industrial biker boots similar to what she wore in Mere Brother Ki Dulhan."

'Challa', the first track to release from Yash Chopra's upcoming romance, was the most-viewed video on YouTube this week. 'Ishq Shava' is expected to release in the next few days.